Engine starter



July 1s, 1924. 1,501,056

W. L. MCGRATH ENGINE STARTER Filed Feb. l0 1921 Patented `luly 15, 1,924.

UNITED STATES PATENT orifice.

WILLIAM'. L. MCGRATH, OF ELMIRA, NEWYORK, ASSIGNOR- T0 ECLIPSE MACHINE COMPANY, OF ELMIRA, NEW YORK, A CORPORATION F NEW YORK.

ENGINE STARTER.

Application filed February 10, 1921. Serial No. 443,772.

T o all whom t may concern.'

Beit known that' I, WILLIAM L. Mo- GRATH, a citizen of the United States, residing atElmira, in the county of Ghemung and State of New York, have invented certain new and useful Improvements in Engine Starters, of which the following is a specification.

My invention relates to a drive or transmission for a starter for an engine, such as an internal combustion engine, and the ob; ject thereof is to improve the structure and 'mode of operation of a certain type of such a drive characterized by a rotatable shaft on which a driving member or pinion is mounted for free longitudinal and rotary movement thereon, andalso. for rotary movement therewith and, when in engagement with a member of the engine, such as the flywheelfthereof, adapted to be clamped to the rotatable member or shaft by means of a control memberor nut having :an automatic longitudinal movement therewith. Speaking in general terms,` the improvement consists in providing a drive of this type with positive clutch means, of Lnovel construction and operation, between the driving member and the control member.

Moreover, my structure is such that in case of any stoppage of the pinion at a point intermediate its length of longitudinal movement (as for instance when the pinion and iywheel abut end to end)I the consequent Jamming action will be automatically relieved by releasing the pressure of the control member against the pinion and thereby releasing the pressure of the pinion against the flywheel.

In the drawing Fig. 1 is aplan view partly a detail view on a larger scale illustrating co-operating parts of the driving member and the control member; Fig. 3 a section on the irregular lines 3-.3 of Fig. 2; Fig. 4 a section on the line 4 4 of Fig. 5; Fig.,'5 an elevation' of one end of the driving member; Fig. 6 an elevation of one end of the` single reduction, and also the outboard vain section embodying my invention; Fig. 2

riety, but it will be understood that my invention may be embodied in other constructions and also in the varieties known as the double reduction and the inboard.

Referring to the embodiment herein illustrated, the prime mover, which is an electric motor indicatedat 1, is provided with an extended armature shaft 2 on which is mounted a shaft in the form of a sleeve provided with a screw threaded portion 3 and a smooth portion 4, such shaft being provided at its outer end with a stop 5. This shaft is provided with a head 6 operatively connected with the Shaft 2 through the driving head or collar 7 secured to such shaft by the stud 8'and through a yielding driving connection 'such as the drive spring 9, whose opposite ends are anchored respectively to the stud 8 and to the stud 10, the latter being secured to the head 6.

Upon the screw shaft there is mounted for free movement a driving member which is in the form of a pinion 11 adapted to enga e or mesh with a member of the engine to e started, such as with the teeth 12 of the flywheel 13. `This pinion is held in its normal position, shown in Fig. 1, by a yielding means such as the spring 14' and the longitudinally movable collar 15 interposed between the pinion and such spring.

The pinion 11 is provided at one end with a disk 16- having contact surfaces 17, and.

also transverse grooves 18.

The controlmember is here in the form of a nut'19 threaded unto the threaded portion 3 of the screw shaft whereby the same has arr automatic longitudinal movement when such shaft is rotated. This nut is provided with a disk 20, having adjacent to the disk 16 contact surfaces 21 and lalso two ribs 22 adapted to co-operate with the grooves 18, The sides of the grooves 18 are straight, being made by transverse cut diametrical of the pinion. The sides 23 of the ribs '22 converge outwardly, with the result that when the grooves and ribs are co-operating as a positive clutch the sides of the ribsl and the sides ofthe grooves constituting the driving faces ofthe clutch are in full contact.- Moreover, the grooves are materially wider than the ribs, and furthermore, by preference, the

ygrooves are sli htly' reater in depth than the thickness o the ri s as shown in Fig. 2,

so that the contact Surfaces 17 and 21 of the pinion and nut will-take the thrust of the screw action of the nut.

Describing the cycle of operation and Vstarting withthe parts in their normal position shown in Fig. 2, when the motor is operated the screw shaft is rotated with the result that the nut 19 isautomatica'lly moved longitudinally to the left along the screw threaded portion of the shaft; carrying the pinion longitudinally in the same direction ecause of the contact of the disks 16 and 20. In this longitudinal movement the pinion is mshed with the flywheel and after the collar 15, and consequently, the pinion has been arrested in its longitudinal movement by the sto clamped to the s eeve shaft by the screw action of the nut. groovesand ribs are at this time already in co-operative relationship, the nut will move rotarily slightly until the sides of the grooves and ribs contact in driving relationship, whereupon the pinion will partake of the rotary movement of this shaft and the engine will be rotated. InV the event that the grooves and ribs are at such time not in co-operating relationship andin the event further of considerable resistance from the flywheel, the nut willmove angularly until such ooves and ribs register, whereupon a posltive clutch is established between the pinion and the nut, whereupon the pinion will be rotated by its shaft and the flywheel, consequently, rotated. After the engine starts on its own power the nut will 'oe returned to the normal position shown in, Fig.

1 by reason of its excess of speed (imparted i to it from the iywheel through the medium of the pinion) over that of the screw shaft `and the pinion will be demeshed and returned to normal position by the spring 14.

In case of the abutting of theA pinion againstv the iywheel when the teeth thereof do not register and therefore do not mesh, thel torque will continue to be transmitted from the vmotor to the drive until a stall torque is'reached whereupon the motor will stop. The -current being thereupon cut off from the motor at the switch 24, the stored up energy in the drive spring will revolve the motor armature and consequently the shaft in a reverse direction. This reverse rotation. is imparted to the control member whose ribs Iwill be moved away from4 the driving face of the grooves and caused to hit somewhat forcibly against the opposite face of the grooves, thereby stopping the rotaryl movement of the control member with the shaft and also breaking loosethe frictional connection between the teeth of the shaft and control member. As a result,

'the control member is moved backwardly lon itudinally by reason of the continued bac ward rotation of the shaft and the 5, such pinion will be- In the event that the pressure of the control member against the. Y

thereof, a control member mounted for 7 automatic longitudinal movement thereof and rotary movement therewith, and clutch means adapted to operatively connect the two members for positive driving when the driving member is stopped in its longitudi- 8 nal movement, said two members being capable of free angular movement when they are in normal position. N

'2. An engine starter drive including a rotatable driving shaft, a driving member 8 mounted for free movement longitudinally thereof, a control member mounted for r automatic longitudinal movement ment thereof and rotary movement therewith, said two members having complemen- 9 tary contact surfaces and also positive clutch means, whereby such control member may clamp the driving member to the shaft after'it has stopped in its longitudinal movement, said two members' being lcapable of free angular movement when they are in normal position.

3. An engine starter rotatable screw shaft, a driving member mounted for free movement longitudinally l thereof, and a control member threaded on the shaft for. automatic longitudinal move'- ment thereofV and rotary movement therewith, said control member in its longitudinalmovement being adapted to contact the l driving member and by its screw action on the shaft, to clamp the latter to the shaft for rotary movement therewithwhen such driving `member is stopped in its longitudinal movement, said driving and control 1 members being provided with positive clutch means which operate under the condition of excessive resistance from the engine member, said two members being capable of free angular movement when they are in norl mal position.

4. An engine starter drive including a rotatable screw shaft, a driving member drive including a/ mounted thereon for free movement longli under the condition of excessive resistance,

from the engine member, said clutch means comprising a groove m one of said members and a cooperating rib in the other member,

said two members being capable of free angular movement when they are in normal position.

5. An engine starter drive including a rotatable shaft, a driving member mounted for free movement longitudinally thereof, and a control member mounted for automatic longitudinal movement thereof and rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp the latter to theshaft for rotary movement therewith when such driving member is stopped'in its longitudinal movement, said driving and control members having an unlimited angular movement, one with respect to the other, until the driving member is so stopped in its longitudinal movement and having means for thereafter limiting such angular movement.

6. An engine starter drive including` a rotatable shaft, a driving member mounted for free movement longitudinally thereof,

and a control member mounted for'auto- -maticA longitudinal movement thereof and A, comprising Aa groove in one of said members anda cooperating rib in the other member, said lgroove being considerably wider than .7. An engine starterv drive including a rotatable shaft, a driving member mounted lfor free movement longitudinally thereof,

and a control member mounted for auto-l matic longitudinal movement thereof and clamp the latter to the shaft for rotary movement therewith when such driving member is stopped in its longitudinal movement, said driving and control members being normally separate and free of each other and being provided with positive Aclutcl means comprising a groove in one of sai members and a cooperating rib 'in the other member, the drivingl faces of the groove and rib being so made as to be in full contact when driving, said driving member having a free longitudinal movement with respect to the control member.

8. An engine starter drive including a rotatable shaft, a driving member mounted for free movement longitudinally thereof, and a control member mounted for automatic longitudinal movement thereof andv rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp the latter to the' shaft for rotary movement therewith when such driving member is stopped in its longitudinal movement, said driving and control members being normally separate and free of each other and being provided with positive clutch means comprising a groove in one of said members and a cooperating rib in the other member, the sides of the rib eX- tending convergingly outwardly and the sides of the groove being parallel.

9. An engine starter drive including a rotatable shaft, a driving member mounted for free movement longitudinally thereof, and a control member mounted for automatic longitudinal movement thereof and rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp'the latter to the shaft for rotary' movement therewith when such driving member is stopped in its longitudinal movement, said driving and*l control members being normally separate and free of each other and being provided with positive clutchl means comprising a groove in one of said members and a cooperating rib in the other member, the driving faces ofthe groove andV rib being so made as to be in full contact when driving, said groove being materially wider than the rib, said driving member having a free longitudinal movement with respect to the controlmember.

10. rotatable shaft, a driving member mounted for free movement longitudinally thereof, and a control member mounted for automatic longitudinal movement thereof and rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp the ,latter .to the 'shaft for'- rotary movement therewith when such driving member is stopped in its longitudinal movement, said driving and control members being normallyseparate and free of each other and being each provided with a disk, said disks being arranged in parallel planes, and having complementary clutch means on their adjacent faces. I

11. An yengine starter drive including a' rotatablef'sha'ft, a driving member mounted yfor free movement longitudinally thereof,

An engine starter drive including a and a control member mounted for automatic longitudinal movement thereof and rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp the latter to the shaft for rotary movement therewith when such driving member is stopped in its longitudinal move-l ment, said driving and control members being normally separate and free of each other and being each provided with a disk, such disks being arranged in parallel planes and one of them having a transverse groove and the other a transverse rib, 4said groove and rib being located on the adjacent faces of the two disks and adapted to cooperate with each other.

l 12. An engine starter drive including a rotatable shaft, a driving member mounted for free movement 'longitudinally thereof, and a control member mounted for automatic longitudinal -movement thereof and rotary movement therewith, said control member in its longitudinal movement being adapted to contact the driving member and clamp the latter to the shaft for rotary movement therewith when such driving member is stop ed in its longitudinal movement, said driving and control members being provided with positive clutch means comprising a groove in one of said members and a cooperating rib in the other member, the groove being greater in depth than the rib in thickness.

13. An engine starter drive including a rotatable driving shaft, a driving member mounted for free movement longitudinally thereof, and adapted to engagefa member of the engine to be started, a control member mounted for automatic longitudinal movement of such shaft and rotary movement therewith, and means for releasing the pressure of the control member against the n driving member in case of stoppage of such driving member at an intermediate point in its longitudinal movement.

14. n engine starter drive including a rotatable driving shaft, a driving member .mounted `for free movement longitudinally A thereof, and adapted to engage a member of the engine to be started, a control member mounted for automatick longitudinal movement of such shaft and rotary movement therewith, and means for causing end -movementof thel control member backwardly. to release the pressure of the driving member against the engine member in case of stoppage of suchl driving member thereby.

15. An engine starter drive including a rotatable driving shaft, a drivin member mounted for free movement longltudinally.

thereof, and adapted to engage a member of the engine to be started, a control member mounted `for automatic longitudinal move- 65 ment of such shaft and rotary movement weinte therewith, and means for rotating the control member backwardly to release the pressure of the control member against the driving member in case of stoppage of such driving member at an intermediate point in its longitudinal movement.-

16. An engine starter drive including a rotatable driving shaft, a driving member mounted for free movement longitudinally thereof, and adapted to engage a member of the engine to be started, a control member mounted for. automatic longitudinal movement of such shaft and rotary movementtherewith, and means including a torsion spring cooperating with said shaft adapted to nrotate such shaft backwardly and thereby cause a backward end movement of the control member to release the driving member in case of stoppage of such driving member at an intermediate point in its longitudinal movement. Y

17. An engine starter drive including a rotatable driving shaft, a driving member mounted for free movement longitudinally thereof, and adapted to engage a member of the engine to be started, a-control' member mounted for4 automatic longitudinal movement of such shaft and rotary movement therewith, and means for releasing the pressure of thev control member against the driving member in case of stoppage of such driving member at an intermediate point in its longitudinal movement, said means including a clutch between the driving and control members and an element for causing backward movement of the control member -in said case.

18.v An engine starter drive includin a rotatable driving shaft, a ldrivin mem er mounted for free movement longitudinally thereof,land adapted to engage amember of the engine to be started, a control member mounted for automatic longitudinal movement of such shaft and rotary movement therewith, and means for releasing the pressure of the control member against the driving member in case 01E/stoppage of such driving member at an intermediate point in its longitudinal movement, said means including a clutch between the driving androtatable driving shaft, a driving member mounted for free movement longitudinally thereof, andA adapted to engagea member of the engine to be started, a control member mounted for automatic longitudinal movement of such'shaft and rotary `movement therewith, and means for releasing the i pressure of the control member against the driving` member in case of stoppage of such driving member at an intermediate point in its longitudinal movement, said means including a clutch between the driving and controlmembers comprising grooves and ribs on said latter two members, the rooves being wider than the ribs, and also including an element for causing backward movement of the control member insaid case.v

20. An engine starter drive includin a rotatable driving shaft, a drivin mem r mounted for free movement longitudinally thereof, and adapted to engagea member of the engine to be started, a control member mounted for automatic longitudinal movement. of such shaft and rotary movement therewith, and means for releasing the pressuren of the control member against the ri'ving member in case of stoppage of such driving member at an intermediate in its longitudinal movement. v

21. A n engine starter drive including a rotatable screwsliaft, a inion mounted for point free movement Vlongitu inally thereof, for

engagement with a member of they en ine to v be started, a control member threa ed on the shaft and adapted to control the advance lon 'tudinal Vmovement of the pinion and to c amp the same to the shaft for rotary movement therewith, clutch means between the pinion and driving member, and means for rotating the shaft backwardly and thereby-move the\control mem.

ber backwardly to' release the pressure of the pinion against the engine member in case of end to end abutting thereof.

22.`An engine starter drive includin a rotatable driving shaft, a driving. mem r mountedffor free movement longitudinally thereof, and adapted to engage a member of the engine to be started, a control member mounted for automatic longitudinal movement of such shaft and 'rotary movement therewith, and a drive spring arranged in the line of transmission of power and adapted to be wound up in the forward direction of rotationy and alsoadapted, be-

cause of its stored up energy, to cause baal:- ward movement of the control member 1n member at case of stop age of the drivin edi ongitudinal an interm fate point in its movement.

23. An engine starter drive' includin rotatable driving shaft, a drivin mem r mounted forfree movement longitudinally thereof, and adapted to engage a member of v the engine to be started, a control member mounted for automatic longitudinal movement of such shaft and rotary movement therewith, and automatic means for reversing the direction ofv rotation of tlie shaft jin case of stoppa e of such driving member at an interme iate point in its lon itudinal movement and thereby relieve it rom the pressure of the control member.

v24. An engine starter drive includin a rotatable driving shaft, a drivin mem r mounted for free movement longitudinally thereof, and adapted to engage a member of the engine to be started, a control member mounted for automatic longitudinal movement of such shaft and rotary movement therewith, and au torsion drive s ring cooperating with the shaft and a apted to be wound u vin the forward direction of rotation and y its stored up energy adapted to reverse the direction of rotation of vsuch shaft to thereby release the pressure of the 'control member against the driving member in case of stoppage of the latter at an intermediate point in its longitudinal movement.

25. An engine starter drive including a l rotatable shaft, a driving member mounted for free movement longitudinally thereof,

'and a control member mounted for longitudinal movement thereof and rotary movement therewith and coo ratin ,with the driving member to estab ishA driving relation between the shaft and a member of the engine to be started, said two members being capable of free angular movement when in normal position and of a limited angular movement in other positions.

26. An engine starterl drive including): rotatable driving shaft, a driving mem r mounted for free movement longitudinally the en e to started, andclutch means adapte to operatively .connectY the two members for positive driving when the drivin member, is in its lungitudina movement. WILLIAM L. MoGRATH.-f :,p"^

thereof, and a control member mountedv for i 

